CT scanner using injected contrast agent and method of use

1. A CT scanner comprising:

at least one first X-ray source and at least one second X-ray source;

a detector arrangement adapted to receive radiation generated by the first and second sources; and

a system controller which is operable to:

monitor build-up of an injected contrast agent utilizing radiation from the at least one first source detected by the detector arrangement in a selected region of interest of a patient;

perform diagnostic scanning utilizing radiation from each second source, detected by the detector arrangement.

2. A CT scanner according to claim 1 , further including at least one third X-ray source wherein the controller operates the at least one third source in conjunction with the second source to perform diagnostic scanning.

3. A CT scanner according to claim 1 , wherein the controller operates one or more of the X-ray sources to perform a preliminary scan of the patient prior to injection of the contrast agent, and applies a graphical representation of the region of interest to a preliminary image resulting from the preliminary scan.

4. A CT scanner according to claim 3 , wherein the preliminary image is a planar image and the preliminary scan is a planar scan.

5. A CT scanner according to claim 3 , wherein the preliminary image and the preliminary scan are rotational CT scans.

6. A CT scanner according to claim 1 , wherein the detector arrangement is comprised of a plurality of detectors, each respectively associated with one of the first and second X-ray sources.

7. A CT scanner according claim 1 , wherein the detector arrangement is comprised of a single detector, receiving radiation from all of the X-ray sources.

8. A CT scanner according to claim 1 , wherein the detector arrangement is comprised of a plurality of matching relatively movable parts, each part respectively associated with one of the first and second X-ray sources.

9. A CT scanner according to claim 8 , wherein at least two of the detector parts are adapted to be arranged in abutting relationship.

10. A CT scanner according to claim 1 , wherein the first and second X-ray sources are offset circumferentially about a scanner rotation axis.

11. A CT scanner according claim 1 , wherein the first and second X-ray sources are spaced apart in a direction parallel to a scanner rotation axis.

12. A CT scanner according to claim 1 , wherein the controller operates the first source in conjunction with the second source to perform diagnostic scanning.

13. A CT scanner according to claim 1 , further including one or more adjustable collimators to direct X-ray beams emitted by the X-ray sources to cover the required portions of the patient for contrast monitoring and diagnostic imaging.

14. A CT scanner according to claim 13 , wherein each collimator is adjustable by the system controller.

15. A CT scanner according to claim 1 , wherein the at least first X-ray source used to monitor the build up of the injected contrast agent emits an X-ray beam at a lower power than the at least second X-ray sources used for the diagnostic scanning.

16. A CT scanner according to claim 1 , wherein each first source is a fan beam source and each second source is a cone beam source.

17. A CT scanner according to claim 1 , wherein the X-ray sources include at least one of one or more separate X-ray tubes, one or more vacuum enclosures with multiple anode and cathode pairs, and an X-ray tube that emits radiation from multiple focal points on an anode surface responsive to deflection of an electron beam.

18. A method of performing CT scanning with an apparatus comprising first and second X-ray beam sources, the method comprising:

providing an injection of a contrast agent to a patient;

monitoring the buildup of contrast agent in the patient in a selected region of interest using the first source; and

performing diagnostic scanning of the patient using the second source when the monitored buildup of the contrast agent reaches a desired level.

19. A method according to claim 18 , and including performing the diagnostic scanning using at least one third x-ray source in conjunction with the second source.

20. A method according to claim 19 wherein the diagnostic scanning is performed utilizing said first, second and third sources.

21. A method according to claim 18 wherein the diagnostic scanning is performed utilizing said first and second sources.

22. A method according to claim 18 , further including:

performing a preliminary scan of the patient prior to injection of the contrast agent; and

applying a graphical representation of the region of interest to an image resulting from the preliminary scan.

23. A method according to claim 22 , wherein the preliminary scan is performed using the first X-ray beam source.

24. A method according to claim 22 , wherein the image resulting from the preliminary scan is a planar image.

25. A method according to claim 22 , wherein the image resulting from the preliminary scan is a CT image.

26. A method according to claim 18 , further including adjusting the positioning of the first and second X-ray sources in a direction parallel to a scanner rotation axis.

27. A method according to claim 18 and including offsetting the X-ray sources circumferentially relative to each other about a scanner rotation axis.

28. A method according to claim 18 , wherein the apparatus further includes one or more adjustable collimators, and wherein the method further includes adjusting each collimator to direct X-ray beams emitted by the X-ray sources to cover the required portions of the patient.

29. A method according to claim 18 , wherein the method further includes adjusting X-ray power of the first X-ray source to a lower level during said monitoring than the second X-ray source during said diagnostic scanning.

30. A method according to claim 18 comprising generating a series of bolus tracking images from the first source.

31. The method according to claim 30 , wherein the bolus tracking images are planar images.